Protective cage structure for tubular gauges



Filed Dec. 6, 1949 3 Sheets-Sues: 1

Jpui30Q1953 I I F. BOEHM 2,643,546

faomc'nvra cm: smucmm FOR TuBuL'm GAUGES F. BoEHM PRoTsc'rm cm mums FORamass 3 Sheets-Sheet 2 Filed Dec. 6. 1949 June 30, 1953 F. BOEHMPROTECTIVE CAGE STRUCTURE FOR TUBULAR Lemmas Filed Dec. 6, 194a M .iYQVi i l llllll FIJIIIIILF:

Patented June 30, 1953 PROTECTIVE CAGE STRUCTURE FOR TUBULAR GAUGESFrederick Boehm, Philadelphia, Pa., assignor to Schutte & Koerting 00.,Philadelphia, Pa., a

corporation of Pennsylvania Application December 6, 1949, Serial No.131,311

This invention relates to improvements in rotameters and a primaryobject of the invention is to provide a generally improved assemblyhaving a number of novel and desirable structural characteristicshereinafter set forth.

A more specific object of the invention is to provide a rotameterassembly having inlet and outlet elements independently adjustablethrough angles of 360 degrees about the axis of the flow tube so as toafford a high degree of flexibility in the attachment of the rotameterassembly to the associated pipe system.

Another object of the invention is to provide an assembly which includesan outer transparent tubular casing for the flow tube as a protectionfor the latter.

Another object of the invention is to provide an assembly which includesan armored cage or jacket constructed so as to facilitate assembly anddisassembly of the rotameter.

Still another object of the invention is to provide an assembly whereinthe aforesaid protection tube and armored cage constitute functionalelements of a packing gland which form sealed connections between theopposite ends of the flow tube and the inlet and outlet fittings.

A further object of the invention is to provide a rotameter assemblyincluding an armored cage or jacket as aforesaid which includes as anele-- ment of the cage or jacket structure means for holding theassembly together, said means being of a character to afford quickengagement and release to facilitate assembly and disassembly of therotameter parts.

A still further object of the invention is to provide a rotameterassembly wherein tie-rods or other threaded fastenings are eliminated.

Still another object of the invention is to provide an assemblyincluding an outer frame in the form of an armored cage or jacket whichmay be produced from bar stock and which thereby avoids the need forcastings.

The invention also contemplates an assembly which is adaptabl either tothe use of guide rods for the float element of the rotameter or to tubesof the type wherein the guide means is an integral part of the fiow tubestructure.

The invention resides also in certain novel structural details anddevices hereinafter devices hereinafter described and illustrated in theattached drawings, wherein:

Fig. 1 is a front elevational view of a rotameter assembly made inaccordance with the invention;

Fig. 2 is a side elevational view of the assembly;

Fig. 3 is a longitudinal sectional view of the assembly illustrated inFigs. land 2;

Claims. (Cl. 73-209) Fig. 4 is an exploded view in perspective showingcomplementary elements of the cage or jacket structure; Fig. 5 is anelevational and partial sectional view illustrating a modified form ofassembly;

Fig. 6 is a section on the line 6-6, Fig. 5;

Fig. '7 is a fragmentary section on the line 1-l, Fig. 6, and

Fig. 8 is a sectional view on the line 8B, Fig. 5.

With reference to Figs. 1 to 4 inclusive, the rotameter assembly thereinillustrated as an embodiment of my invention comprises a flow tube l ofglass or transparent plastic having the typical longitudinally taperedform; and a float 2 which coacts with the flow tube l in well knownmanner to afford the required flow measurements. In the present instanceth float 2 is guided in its movement in the tube by a guide rod 3 whichextends centrally and longitudinally of the tube and which is supportedby means hereinafter described.

The rotameter assembly further comprises a protective tube or casing lof glass or plastic, transparent or otherwise, which embraces the flowtube l but which is somewhat shorter than that tube I so as to providefor engagement of the ends of the tube l by a pair of packing ele+ ments5 and 6. These elements 6 are of annular form and closely embrace theouter surface of the tube l at the opposite ends of the latter, as bestshown in Fig. 3. As also shown in this figure the opposite ends of thecylindrical casing 4 contact the confronting sides of the packing rings5 and 6 respectively.

The tube 1 finds a seat upon a lower terminal member or fitting l, agasket 8 being interposed between the tube and the inner face of saidmember I. The member 1' has a cylindrical bore 9 which, in assembly,aligns with the tube and is in direct communication with the lower endof the latter. The lower or outer end of the bore 9 is threaded forreception of a plug l I which closes the lower end of the bore and thisplug is provided with a recess l2 which neatly receives the lower end ofthe guide rod 3. In the present instance the lower end of the rod 3 isembraced by a sleeve l3 which seats against the inner face of the plug 1I and forms a stop to limit the downward movement of the float 2 in thetube I and bore 9. The member I, which is substantially rectangular inform, has in one side thereof an opening M which is tapped for receptionof the threaded end of a pipe l5 constituting an element of the systemin which the rotameter may be installed. The member 1 has at its upperend a recess 16 which extends completely around the upper end of thefitting in a plane normal to the longitudinal axis of the bore 9, thecylindrical bottom of said recess being coaxial with the bore 9. Aradially projecting terminal flange IT at the upper end of the saidmember forms one side wall of the recess I6. The function of the recessand flange will be described hereinafter.

A corresponding terminal member or fitting I8 is provided at the upperend of the assembly, this member having a central bore I9 which alignswith the tube I and which is closed at the upper end by means of a screwplug 2| corresponding to the plug II at the lower end of the assembly.Like the plug I I, the plug 2I has a recess 22 in its inner face whichreceives the upper end of the guide rod 3 whereby the rod is heldaccurately in coaxial relation with and in the flow tube I. The member I8 has in one side thereof a tapped opening 23 which receives thethreaded end of a pipe 24 constituting an element of the fluid system inwhich the rotameter may be installed. Adjacent its lower end the memberI8 is provided with a recess 25 which extends completely around themember in a plane normal to the axis of the bore I9 and which has acylindrical bottom coaxial with the said bore. As in the case of therecess I6 of the member I, the recess 25 defines the inner side of aradially projecting terminal flange .26 at the lower end of the memberI8.

In assembly the upper end of the tube I is embraced by the terminalflange portion of the member I8 and the outer surface of the flange 26seats against the packing ring 5. At the opposite end of the cylindricalcasing 4 the packing ring 6 finds a seat upon the upper face of theterminal flange ll of the member I, the said ring contacting the outerface of the gasket 8.

The assembly also includes an outer cage or jacket consisting of theelements shown in Fig. 4. In effect this cage consists of three parts ofwhich one is indicated by the reference numeral 21. This member isexternally of rectangular form corresponding dimensionally with theterminal members I and I8 described above and having an innercylindrical bore 28 which in assembly embraces the lower part of thecasing 4. At its lower end the bore 28 terminates at an inturned flange29 which in assembly projects into the recess I6 of the member 1, asbest illustrated in Fig. 3, and which thereby engages behind theterminal flange I! of that member, the inner surface of the flange 29being cylindrical and conforming dimensionally with the cylindricalbottom of the recess I6. The terminal opening at the bottom of the cagemember which is defined by inner cylindrical surface of the flange 29 isdesignated by the reference numeral 3|. In this manner the cage member21 is interlocked with the member 1 for a purpose hereinafter described.

Two opposite walls 32 and 33 of the member 21 have secured thereto clampelements, designated generally by the reference numerals 34 and 35; andthe other side walls 36 and 31 of the member are cut awaylongitudinally, as indicated at 38 and 39 respectively, to provideopenings through which in assembly the tubular casing 4 is exposed. Ateach corner of the upper terminal surface M of the member 21 a pin 42projects parallel to the sides of the member and normal to the plane ofthe said terminal surface M. It will be noted that the body of themember 21 is composed of two separate parts which are separated by alongitudinal slot 43 and which are held together in 4 fixed relation butdetachably by the elements of the clamps 34 and 35.

The cage further comprises the elements 44 and 45 shown at the top ofFig. 4. These two elements constitute the halves of the upper portion ofthe cage and jointly form a cage end section corresponding in form tothe member 21. Each of the members has at its upper end an inturnedterminal flange, 46 and 41 respectively, which in assembly projects intothe recess 25 of the member l8 and engages behind the terminal flange 26as shown in Fig. 3 to interlock the elements 44 and 45 with the memberI8 for the purpose set forth below. At the lower ends the elements 44are provided with longitudinal bores 48, one at each corner, which inassembly receive the pins 42 of the member 21 wherein the three partsare united into a unitary cage structure which once assembled holdsflanges 46, 41 and 29 unyielding in recesses 25 and I6. Complementaryrecesses 49, 49 in the opposite sides of each of the members 44 and 45form openings in the sides which correspond to and register with theopenings 38 and 39 in the sides of the member 2! so that these openingsin effect extend substantially the full length of the cage and expose acorresponding portion of the cylinder 4.

Each of the sections 44 and 45 has attached to the unrecessed wall 5Ithereof a clamping element, 52 and 53 respectively, and in assemblythese elements cooperate respectively with the clamping elements 34 and35 on the member 21 to unite the sections longitudinally. These clampsare of well known type which function by toggle action to draw thesections 44 and 45 and the section 21 together so that the terminalmember I8 moving as a unit with the sections 44 and 45 is drawn tightlydown against the packing member 5 which in turn creates pressure forcingthe cylinder 4 downwardly against the packing member 6 and the latteragainst the opposed face of the terminal member 1. By this action, madepossible by the aforesaid interlocked relation between the cage sections44-45 and 21 and the terminal members I8 and I, the packing members 5and 6 are expanded radially so as to bear tightly against the outer faceof the floW tube I and the inner faces of the cage structure describedabove. The several elements of the assembly are in this manner securedtogether in a rigid unitary assembly wherein the joints between the flowtube I and the terminal members I and I8 are effectively sealed by theexpanded resilient packing rings 5 and 6. These rings also effectivelyseal the joints between the ends of the casing member 4 and the saidterminal members I and I8 and it will be noted that the action is suchthat the cylindrical member 4 functions in effect as a gland or followerto forcibly expand the packing element 6 in the stuffing box formedbetween the wall of the tube I, the end surface of the terminal member Iand the wall of the cage. The terminal flange 26 of the member I8functions also in the capacity of a gland to expand the packing member 5in the stuffing box formed by the wall of the tube I, the embracing wallof the cage and the upper end of the cylinder 4. The glands are actuatedto compress the packing by means of the clamps 34-52 which draw theparts of the cage together and which by reason of the interlockedconnection between the elements of the cage and the members I and I8 actin effect to draw the member I8 downwardly against the packing 5 and thepacking 5 against the top of the cylinder 4. It will be noted thatavoided.

the upper portion of the cage consisting of the elements 44 and 45 isdivided along a plane at right angles to the plane of the slot 43 of thelower member 21 of the cage.

The aforedescribed construction confers certain highly desirablecharacteristics upon the rotameter assembly. Each of the terminalmembers and I8, for example, may be adjusted with respect to the body ofthe rotameter through an angle of 360 degrees about the longitudinalaxis of the tube This affords a high degree of flexibility in mountingthe rotameter in the fluid system of which it is to form a part. By useof the quick acting clamps 34-52 and 35-53 and the pins 42 the necessityfor tie-rods and like threaded elements has been eliminated and theoperations of assembly and disassembly are greatly facilitated. Thecasing cylinder 4, which may be made of glass or other suitabletransparent material, affords a high degree of protection for the flowtube without interfering with the visibility of the tube, and the mannerin which this tube is associated With the other elements of thestructure materially simplifies the means for sealing the flow tube inthe structure. The construction also utilizes the terminal members andI8 and the casing 4 as functional elements of the stuffing boxes whichare required to properly seal the flow tube in the duct system, withresultant material simplification. The armored cage or jacket not onlyprovides the necessary rigidity to the frame structure, but alsoconstitutes a functional part of the sealing means, and the constructionof the cage is such as to materially facilitate the operations ofassembly and disassembly.

It will be noted that the two parts of the lower member 2'5 of the cagewill be assembled with the lower terminal member 1 prior to attachmentof the clamps 34 and 35 which, as previously described, function'tosecure the two halves of the casing member 21 together. Assembly of theupper portion of the cage is effected by first applying the two cagehalves 44 and 45 to the upper terminal member l8 and thereafterinserting the pins 42 in the recesses 48 to unite the members 44 and 45with the lower member 21, the pins 42 then functioning to hold the upperelements 44 and 45 in their subassembled relation with the member l8 andto prevent relative angular movements between the cage sections aboutthe longitudinal axis of the cage. The upper and lower packing rings 5and 6 and the intervening cylinder 4 may be assembled with the fiow tubeand inserted in the lower member 21 of the cage structure prior toconnecting the latter with the sub-assembly consisting, as describedabove, of the two upper elements 44 and 45 of the cage and the upperterminal member l8. Access may be had to the interior of the flow tube Iafter assembly for cleaning purposes or for removal of the guide rod 3and the float 2 by removal of the plugs and 2 I.

Additionally, the cage or jacket is of a character permitting readyproduction thereof by machining from bar stock so that castings are Itwill be apparent that the tube and the guide rod 3 may be replaced byother forms of flow tube or by tubes utilizing other float guidingmeans, such, for example, as integral ribs projecting from the innertapered surface of the tube.

The embodiment of the invention illustrated in Figs. 5 to 8 inclusivediffers in certain details from that described above. The flow tube,identified in this instance by the reference numeral 55,. is of a typecontaining internal ribs 56 as guides for the float 51. The tube 55 issurrounded by an outer casing tube 58 of glass or other suitabletransparent material and the opposite ends of the cylinder 58 seatagainst upper and lower packing rings 59 and 5| respectively. As in theprevious embodiment, an outer cage or jacket 62 is provided whichcomprises a lower portion 63 and an upper portion 64. In this case theportions 63 and 64- are secured together by means of screws 55. Theupper end of the upper portion 64 of the cage is provided with aninturned flange 66 (see Fig. 7) which engages behind a shoulder 61 of anannular member 55, the lower end of which in assembly seats against thepacking ring 59, and the member 58 also comprises an outwardly extendingthreaded neck 69 which in assembly is threaded into a tapped opening llin an upper terminal member 12, as shown in Fig. '7. The member 68 isprovided with holes 1|] for engagement by a suitable wrench tofacilitate assembly and disassembly of this member with the terminalmember l2. This terminal member is provided at one side with a tappedopening 13 for connection to a system pipe 14. The outer end surface ofthe member 12 is also provided with a tapped opening 15 which isnormally closed by a screw plug 15, this plug in the present instancehaving an inward axial extension TI which functions as an upper limitstop for the float 51.

The lower end of the lower cage member 63 is also provided with aninturned flange 18 which engages behind a shoulder 19 of an annularmember 8| corresponding to the member 68 described above. The innersurface of the member 8| form a bearing for the lower end of the flowtube 55 and a suitable gasket 82 is provided between the end of the tubeand the opposed sur-- face of the annular member. This member also formsa seat for the lower packing ring 6|.

The member 8| is provided with a threaded neck 83 which is adapted toenter a tapped aperture 84 in a lower terminal member 85 and to therebysecure the terminal member in the rotameter structure. Wrench holes 8|!are provided in the member 8| corresponding to the holes 10 in themember 68. This member 85 has a tapped opening 86 in one side wallthereof for connection with a system pipe 81. The member 85 also has atapped opening 88 in the outer end thereof which is normally closed by ascrew plug 89, and threaded into the inner side of the plug 89 is a pin9| which forms a lower limit stop for the float 51, as shown in Fig. 5.

In assembling the above described rotameter structure the sealing rings59 and El are applied to the ends of the flow tube 55 with theprotective cylindrical casing 58 in place between the said rings. Thelower annular member 8| is inserted in the bottom of the lower portion63 of the cage and the subassembly consisting of the flow tube 55, outertube 58 and packing rings 59 and 5| then inserted to rest upon theannular member 8| within the lower cage section. The lower terminalmember 85 may then be threaded onto the neck 83 of the annular member8|. The annular member 68 is then inserted in the upper cage member 64and the upper terminal member 12 threaded to the neck 59 of the member68. Thereafter the upper cage member 64 may be attached to the lowercage member by means of the screws 65. When the screws are tightened theannular member 58 is drawn downwardly with the upper cage member 54against the packing ring 69,

the pressure being applied through this ring to the cylinder 58 which inturn is pulled downwardly against the lower packing ring 6|. The packingrings are thereby expanded between the wall of the flow tubes 55 and theopposed wall of the cage so that a tight seal is effected at both endsof the flow tube and between the flow tube and the annular members 68and BI. The joints between the terminal members 12 and 85 and therespective annula members 68 and BI are sealed by suitable gaskets 92and 93 respectively.

It will be apparent that this embodiment of the invention possesses manyof the desirable characteristics of the previously described embodiment.

I claim:

1. In a protective structure for the fragile transparent tubes of gaugesand the like, the combination with such tube of a flexible sealing ringembracing each end of said tube, a transparent tubular casingsurrounding the tube and confined between said rings, a terminal fittingat each end of the tube abutting the outer end faces of the respectiverings, a cage embracing the casing and having side ports through whichthe casing is visible, said cage comprising separable end sectionsrelatively movable longitudinally of the casing, means for preventingrelative angular movements between the cage sections about thelongitudinal axis of the cage, means for detachably interlocking each ofthe terminal fittings with the proximate cage section for movement withthe latter as a unit in the said longitudinal direction, and means forforcibly drawing the said sections toward each other so as to compresthe sealing rings between the terminal fittings and the respectiveproximate ends of the casing thereby to expand the rings into firmsealing engagement with the outer surface of the tube.

A structure according to claim 1 wherein the means for preventingrelative angular movements between the cage sections consists of pinsprojecting from one of said sections parallel to the said casing axis,and sockets in the other of said sections having a close-sliding fitwith said pins.

3. A structure according to claim 2 wherein each of said cage sectionscomprises two separable longitudinal complementary parts, said structureincluding also means for detachably securin together the complementaryparts of one of said cage sections to form a rigid unit, and the saidpins guiding the complementary parts of the said other case section inthe said drawin movement and, with said drawing means, forming the saidcage sections and the complementary parts thereof into a rigidself-contained unit.

4. A structure according to claim 3 wherein the said means for drawingthe cage sections together includes an element mounted on each of twoopposite sides of the unitary section and separate elements on therespective parts of the other cage section forming complementary pairsrespectively with the elements on the unitary section, a pivoted leveron one of the complementary elements of each pair, and a bail on eachlever for interlocking engagement with the other element of said pair.

5. A structure according to claim 3 wherein each of the cage sectionshas an inturned peripheral flange and the said terminal fittings haveperipheral recesses for reception of said flanges to interlock thefittings with the respective cage sections in direction longitudinallyof the casing while permitting angular adjustment of the fittings withrespect to the cage about the longitudinal axis of the latter.

FREDERICK BOEHM.

References Cited in the file of this patent UNITED STATES PATENTS NumberName Date 1,110,974 Buskirk et a1 Sept. 15, 1914 2,370,634 Brewer Mar.6, 1945 2,426,393 Fischer Aug. 26, 1947 2,475,630 Melas et al July 12,1949

